There is a demand from FA device manufacturers to support a plurality of FA network protocols with the same hardware (hereinafter, H/W), and LSIs that support Ethernet®-based multiple protocols are going into markets. An invention of an LSI that supports multiple protocols has been proposed for a digital multifunction machine, which is not however for an FA device (see, for example, Patent Literature 1). The Patent Literature 1 discloses a multifunction device including a network LSI that can process a high speed connection separately from a low speed connection. When an application requests a high speed connection, the multifunction machine assigns the process to the high speed connection of the network LSI and executes a TCP (Transmission Control Protocol)/IP (Internet Protocol) protocol by H/W processing. Meanwhile, when the application requests a low speed connection, the multifunction machine assigns the process to the low speed connection and performs software (hereinafter, S/W) processing of the TCP/IP protocol in a TCP/IP processing unit that is not the network LSI, without performing the TCP/IP process in the network LSI.